摘要
以不同的凝固速率制备了Cu-10Ag亚共晶合金。铸态结构由初生Ag沉淀,(Cu+Ag)共晶和Cu相组成。采用大变形制备了Cu-10Ag合金原位纤维复合材料。其中由初生Ag沉淀相所形成的Ag纤维具有较大直径(d)并可用幂指数关系d=C·exp(-0.228η)拟合,式中η是真实应变,C是与合金原始晶体尺寸有关的系数,而由(Cu+Ag)共晶中的Ag层所形成的Ag纤维具有更细直径(几纳米)。低温中间热处理可进一步细化Ag纤维尺寸和改进性能。经热机械处理的Cu-10Ag合金原位纳米纤维复合材料具有高强度(σb＞1.5 GPa)和高电导率(＞60％IACS)。大变形Cu-10Ag合金原位纳米纤维复合材料显示了两阶段强化效应。讨论了影响Ag纤维尺寸的因素和复合材料的强化与形变机制。
The Cu-10Ag in situ nano-fibre composite based on the Cu-10Ag alloy with different solidification rates was prepared by heavy deformation. The cast structure of the alloy consists of the primary Ag precipitate, （Cu＋Ag） eutectic and Cu matrix. The rapid solidification refines the original grains and increases the proportion of （Cu＋Ag） eutectic, whereas slow solidification promotes separation of primary Ag precipitate. In the deformation process, the primary Ag precipitate is transformed into relatively coarse fiber, the diameter （at） of which can be approached by an exponential function： d=-C.exp（-0.228η）, here C is a coefficient related to the size of the original grains, whereas the Ag lamellae in the （Cu＋Ag） eutectic colonies transforms finer Ag fibre. A two-stage strengthening effect was observed for deformed alloy. The intermediate annealing at lower temperature in the deformation process refines further Ag fibre and improves properties of the composite. The Cu-10Ag in situ fibre composite experienced thermomechanical processing possesses high tensile strength （σb≥1.5 GPa） and electric conductivity （≥60%IACS）. The strengthening and deformation mechanisms in the Cu-10Ag in situ fibre composite were discussed.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2005年第12期1930-1934,共5页
Rare Metal Materials and Engineering
基金
国家自然科学基金(5037103)
